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Background Temporomandibular joint ankylosis (TMJ ankylosis) manifests itself as a locked jaw and reduced mouth opening. We hypothesized that the efficacy of TMJ ankylosis surgery in a child may largely depend on physiotherapeutic management. Case description : In this case report, we present the treatment of a girl between 1 and 4 years of age, who was unable to open her jaws immediately after birth. Congenital ankylosis was diagnosed. Intervention : Two models of therapeutic management were presented, with a surgical procedure to release bone fusion adopted as a starting point. In the first model, the rehabilitation procedure started 21 days after surgery. Outcomes : Despite rehabilitation, no clinical improvement was achieved (i.e. the child was still unable to open her jaws). In the second model, rehabilitation started from the day after surgery and management according to the second model allowed for obtaining therapeutic benefits. After therapy, the girl was able to abduct the mandible to a degree allowing for improved speech and the ability to crush food. Conclusions : This clinical case shows that the efficacy of surgical procedures may depend on the type of postoperative management. It was demonstrated that physiotherapy started immediately after the procedure to release the ankylosis improved the mandible mobility outcomes for this child.

This study analyzed morphometric and hemodynamic parameters of aneurysmal and non-aneurysmal middle cerebral artery (MCA) bifurcations and their relationship with optimal values derived from the principle of minimum work (PMW). The study included 96 patients with MCA aneurysm and 94 controls. Aneurysm patients presented with significantly higher values of the radius and cross-sectional area of the MCA trunk, angle between the post-bifurcation branches (α angle) and volume flow rate (VFR) and had significantly lower values of junction exponent and pulsatility index than the controls. The Φ1 and Φ2 angles (angles between the MCA trunk axis and the larger and smaller branch, respectively) and α angle in all groups were significantly larger than the optimal PMW-derived angles. The most important independent predictors of MCA aneurysm were junction exponent (odds ratio, OR = 0.42), α angle (OR = 1.07) and VFR (OR = 2.36). Development of cerebral aneurysms might be an independent effect of abnormalities in hemodynamic and morphometric factors. The risk of aneurysm increased proportionally to the deviation of morphometric parameters of the bifurcation from their optimal PMW-derived values. The role of bifurcation angle in aneurysm development needs to be explained in future research as the values of this parameter in both aneurysm patients and non-aneurysmal controls in were scattered considerably around the PMW-derived optimum.

The rehabilitation approach has changed with the appearance of robots. As a results the rehabilitation costs significantly decrease but also time for both the patient [1], who does not have to commute for long time to the office and medical professionals. Nowadays medicine, computer science, electronics, and engineering, in general, are strongly connected. A group of specialists is working on newer and newer solutions to improve both diagnosis and therapy. This article provides an overview of basic rehabilitation robotic solutions used in the rehabilitation of upper limb functions.The literature used is based on PubMed and Scopus databases included articles published between 1999 and 2021. Eligibility criteria included upper limb exoskeletons for rehabilitation of both the wrist, elbow, and shoulder joints.This paper provides an overview of an important research subject and highlights the current knowledge in the field. Despite extensive attempts to develop rehabilitation systems, exoskeletons are primarily uncommercialised despite a large number of prototypes.

Attacks with improvised explosive device (IED) constituted the main threat to, for example, Polish soldiers in Iraq and Afghanistan. Improving safety during transport in an armored vehicle has become an important issue. The main purpose of the presented research is to investigate the mechanism of lower leg injuries during explosion under an armored vehicle. Using a numerical anatomic model of the lower leg, the analysis of the leg position was carried out. In all presented positions, the stress limit of 160 (MPa) was reached, which indicates bone damage. There is a difference in stress distribution in anatomic elements pointing to different injury mechanisms.

Background Conclusions from studies evaluating vessel dimensions and their deviations from the values resulting from the principle of minimum work (PMW) on the formation of intracranial aneurysms (IAs) are still inconclusive. The aim of our study was the morphometric analysis of cerebral arterial bifurcations harbouring aneurysms. Methods The study comprised 147 patients with basilar artery (BA) and middle cerebral artery (MCA) aneurysms, and 106 patients constituting the control group. The following morphometric parameters were evaluated: the radii of vessels forming the bifurcation, the junction exponent, the values of the bifurcation angles (Φ1 and Φ2 angles between the parent vessel trunk axis and the larger or smaller branches, respectively; α angle, total bifurcation angle) and the difference between the predicted optimal and observed branch angles. Results The analysed parameters for internal carotid artery (ICA) bifurcations were not significantly different among the groups. MCA and BA bifurcation angles and the radii of the parent MCA and BA vessels with aneurysms were significantly higher compared to the control group. The differences between the predicted optimal and observed branch angles were significantly higher for BA and MCA bifurcations with aneurysms compared to the control group. The mean junction exponent for bifurcations in the circle of Willis (i.e., ICA and BA bifurcations, respectively) and MCA bifurcations with aneurysms was significantly lower than the theoretical optimum and not significantly different among the groups. In a multilevel multivariate logistic regression analysis, the branch angles and the radius from the parent vessel were significant independent predictors of the presence of IAs. The ROC analysis indicated that the α angle was the best performer in discriminating between aneurysmal and non-aneurysmal bifurcations. Conclusions The dimensions of the arteries forming the circle of Willis do not follow the PMW. The deviation from optimum bifurcation geometry for bifurcations beyond the circle of Willis (particularly a wider radius of the parent artery and a wider total bifurcation angle) may lead to the formation of IAs. Further studies are warranted to investigate the significance of vessel dimensions and the bifurcation angle on the magnitude of the shear stress in the walls of arterial bifurcations.

This work aimed to assess the impact of acellularization and sterilization methods on the mechanical properties of biocomposites used as a skin substitute. On the basis of the statistical analysis, it was ascertained that the values of the Young modulus for the samples before the sterilization process—only in the cases of substances such as: trypsin, 15% glycerol and dispase—changed in a statistically significant way. In the case of dispase, the Young modulus value before the sterilization process amounted to 66.6 MPa, for trypsin this value equalled 33.9 MPa, whereas for 15% glycerol it was 11 MPa. In the case of samples after the completion of the sterilization process, the analysis did not show any statistically significant differences between the obtained results of Young’s modulus depending on the respective reagents applied. It was confirmed that different methods of acellularization and the process of sterilization effect the alteration of mechanical properties of allogeneic skins. In the case of the decellularization method using SDS (Sodium Dodecyl Sulfate), liquid nitrogen and 85% glycerol the highest values of strain were observed. In the authors’ opinion, it is the above-mentioned methods that should be recommended in the process of preparation of skin substitutes.

AIMS: To compare the differences in bone mineral density (BMD) at loaded and non-loaded skeletal sites in professional ballet dancers. We hypothesized that in both male and female elite ballet dancers, a significant difference in BMD will be observed between impact and non-impact sites. METHODS: 44 elite ballet dancers, 22 men (age 26.4±5.9 yrs) and 22 women (age 24.9±5.3 yrs), were examined. BMD measurements were performed using dual-energy x-ray absorptiometry at three skeletal sites—forearm (FA), lumbar spine (LS), and femoral neck (FN)—and analyzed using t-tests, ANOVA, and linear regression models. Information about career duration, training volume, health habits, and menstrual disorders (women) was collected. RESULTS: Z-scores for LS and FN were significantly higher in men than in women. However, Z-scores for FA were similar in men and women and fell below the expected range for age (

Background Previously published computational fluid dynamics (CFD) studies regarding intracranial aneurysm (IA) formation present conflicting results. Our study analysed the involvement of the combination of high wall shear stress (WSS) and a positive WSS gradient (WSSG) in IA formation. Methods We designed a case-control study with a selection of 38 patients with an unruptured middle cerebral artery (MCA) aneurysm and 39 non-aneurysmal controls to determine the involvement of WSS, oscillatory shear index (OSI), the WSSG and its absolute value (absWSSG) in aneurysm formation based on patient-specific CFD simulations using velocity profiles obtained from transcranial colour-coded sonography. Results Among the analysed parameters, only the WSSG had significantly higher values compared to the controls (11.05 vs − 14.76 [Pa/mm], P = 0.020). The WSS, absWSSG and OSI values were not significantly different between the analysed groups. Logistic regression analysis identified WSS and WSSG as significant co-predictors for MCA aneurysm formation, but only the WSSG turned out to be a significant independent prognosticator (OR: 1.009; 95% CI: 1.001–1.017; P = 0.025). Significantly more patients (23/38) in the case group had haemodynamic regions of high WSS combined with a positive WSSG near the bifurcation apex, while in the control group, high WSS was usually accompanied by a negative WSSG (14/39). From the analysis of the ROC curve for WSSG, the area under the curve (AUC) was 0.654, with the optimal cut-off value −0.37 Pa/mm. The largest AUC was recognised for combined WSS and WSSG (AUC = 0.671). Our data confirmed that aneurysms tend to form near the bifurcation apices in regions of high WSS values accompanied by positive WSSG. Conclusions The development of IAs is determined by an independent effect of haemodynamic factors. High WSS impacts MCA aneurysm formation, while a positive WSSG mainly promotes this process.

The main aim of the research presented in this paper is to evaluate the change in radial strength of biodegradable stents at various time intervals. Three polymer stents made of bioresorbable material based on polyesters (PLA) were evaluated. As part of the tests, tests were carried out on three polymer stents made of bioresorbable material based on polyesters (PLA). Radial strength was determined for stents before and after the biodegradation process. The obtained test results enabled the assessment of the impact of the time of biodegradation on the value of the measured force.

Road traffic accidents involving coaches do not happen very often, but they are very dangerous because they affect a large number of passengers. Coaches (or intercity buses) are not equipped with safety belt harnesses. Valid regulations do not impose any obligation on coach manufacturers to provide intercity buses with either two- or three-point safety belts. This fact may result from the unawareness of risks and injuries that might befall the passengers with no safety belts during accidents. That is the reason why this work aims to compare the aftermath of coach accidents with no safety belts and the ones with safety belts. A detailed aim of this research is to analyse the results of dynamic loads during a frontal impact exerted on coach passengers travelling with and without (two- and three-point) safety belts. This objective was achieved by performing experimental studies and modelling which focused on the process of dynamic load transfer on the human body during a traffic accident. The research was conducted parallel on an adult and a child. The equivalent of a 50th percentile male was a hybrid III dummy (M50), whereas a child at the age of about 10 was represented by a P10 dummy. A numerical model was generated and verified in experimental testing in the scope of kinematics. Also, the comparison of the recorded courses of forces, acceleration, and moments was conducted. The results obtained from the tests were analyzed regarding the injury criteria for head, neck, and thorax. It was observed that both for the two-point safety system and the lack of safety belts, there were high values of acceleration recorded in the centre of gravity of the head. On the basis of the investigations conducted, it was ascertained that only a three-point safety belt system ensures the satisfaction of all injury criteria within admissible standards both in the case of criteria defined in the rules no. 80 and the rules no. 94 determined by the United Nations Economic Commission for Europe. It is the three-point safety belt system which should be obligatory in all intercity buses.

One of the least known conditions of the lumbar spine in terms of biomechanics is spondylolisthesis which causes many serious consequences for the patient. This research aimed to perform a mechanical analysis of the origins of spondylolisthesis and its impact on the biomechanics of the lumbar section of the spine. Within the framework of this study, a physiologically model of the lumbar spine was created in the MADYMO software. In the next stage a slip of vertebra L4 was simulated by means of a controlled forward displacement of the vertebral body of vertebra L4. 10 variants of spondylolisthesis (W1–W10) of different degrees were subjected to a biomechanical evaluation. In maximum bending of the physiological spine at an angle of 27° the value of the shear force amounted to 1.9 kN, while for the spine affected by spondylolisthesis with slip grade W9 at the maximum bending of 34° the shear force amounted to 5.5 kN. It was observed that the lumbar spine with the simulated spondylolisthesis had greater mobility in comparison with the physiological spine, which was shown by maximum bending angles (physiological 27°, W9 34°).

The aim of this paper was to evaluate which method of acellularization and sterilization is optimal, in the meaning of which processes have the least impact on the deterioration of mechanical properties of porcine tissues used for xenogeneic applications.The static tensile probe was conducted for 80 skin specimens obtained from transgenic swine, which are used as a wound dressing for skin recipient. Obtained data were subsequently analyzed with the use of statistical methods.It was found that Young's modulus for the samples after the sterilization process for the dispase substance and the mixed method (SDS + trypsin) were statistically significantly changed. In the case of dispase, Young's modulus value before the sterilization process was 12.4 MPa and after the value increased to 28.0 MPa. For the mixed method (SDS + trypsin) before the sterilization process Young's modulus value was 5.6 MPa and after it was increased to 6.3 MPa. The mixed method (SDS + trypsin) had the slightest effect on changing the mechanical properties of the samples before and after the sterilization process.It was confirmed that different methods of acellularization and the process of sterilization have an influence on the change of mechanical properties of the skin of transgenic swine. In the authors' opinion, the mixed method (SDS + trypsin) should be recommended as the best one for the preparation of transgenic porcine dermal dressings because it ensures a smaller probability of dressing's damage during a surgical procedure.

As part of the experiments herein, the mechanical properties of specimens made of poly-ether-ether-ketone (PEEK) material using 3D printing technology were determined. Two populations of specimens were investigated, the first of which contained an amorphous structure, while the other held a crystal structure. The studies also investigated the influence of the print directionality on the mechanical properties obtained. Static tensile, three-point bending, and impact tests were carried out. The results for the effect of the structure type on the tensile properties showed that the modulus of elasticity was approximately 20% higher for the crystal than for the amorphous PEEK form. The Poisson’s ratios were similar, but the ratio was slightly higher for the amorphous samples than the crystalline ones. Furthermore, the studies included a chemical PEEK modification to increase the hydrophilicity. For this purpose, nitrite and hydroxyl groups were introduced into the chain by chemical reactions. The results demonstrate that the modified PEEK specimens had worse thermoplastic properties than the unmodified specimens.

The article presents statistical research aiming at the formulation of functions of the child’s head growth in the first year of age. The research group consisted of 129 infants, from 0 to 12 months of age, whose heads were subjected to computer tomography tests within a regular diagnosis of neurological and oncological diseases and other conditions. On the basis of medical images, 3D models of infants’ skulls were developed. They enabled determination of the coordinates of anatomical points. The craniometric database was subjected to a statistical analysis in order to develop a head growth model. Five directional vectors of the head growth were formulated in particular directions and three functions were proposed. The degree of the functions’ compatibility with empirical data was tested. The best-fitting model was selected for each vector by means of a nonlinear estimation method.

The article-related research work aimed to investigate the effect of the morphometric features of the middle cerebral artery (MCA) on values of hemodynamic parameters present on the artery wall. The research-related tests were performed using the ANSYS® CFX software programme. The objective of the tests involved the development of a parametric model representing the morphometric features of a vessel. The model was based on geometric models of middle cerebral arteries (MCAs) obtained on the basis of angiotomography of patients. Morphometric features subjected to analysis included the radius of the artery inlet and that of the outlet as well as the angle of bifurcation.

Numerical modeling of an IED explosion under an armored vehicle is one of the primary methods of the evaluation of the vehicle crew safety. In the presented paper the authors use numerical models to assess the influence of acceleration pulse on the soldier’s body. This work focuses on the ergonomic aspects of the crew compartment. Simulations show the differences in injury levels depending on various factors e.g. the location of an explosion which changes the direction of load. The simulations results include the injury criteria and kinematics of the soldier’s body. The outcomes enabled the determination of factors and elements of the compartment which can be dangerous for soldiers.

SUMMARY In this paper, the application of new visualization technologies in correction of funnel chest is presented. Often, such defects cause problems with breathing, and therefore, to improve the cardiorespiratory efficiency, a correction is required. The virtual model of chest was formulated to determine the strains and stresses after correction of deformation with using the stabilizing plate. From biomechanical point of view, the knowledge of the load-affecting stabilizer is necessary to select optimal parameters of the plate. The force-affecting plate that was used in the correction of chest deformation by Nuss method was determined on the basis of finite element model of funnel chest. The main aim of this work was to select the optimal thickness of plate. Calculations were conducted for three alternative constraints. Copyright © 2013 John Wiley & Sons, Ltd.

The aim of the study was to develop and verify a model of rally driver with a safety system HANS (head supporting device), which will enable biomechanical analysis of injuries in rally accident.Simulations were carried out in Madymo® software, the results of which were verified based on sled test performed in the Automotive Industry Institute (PIMOT) in Warsaw. The model being verified allowed us to perform a multivariate simulation of rally accident in terms of assessing effectiveness of protection and usefulness of HANS system.Acceleration waveforms of the head and chest were obtained from numerical experiment and also forces and moments occurring in the upper cervical spine. The results obtained allowed driver injuries to be analyzed based on injury criteria of the head and neck: HIC15, NTE, NTF, NCE and NCF.The analysis enabled assessment of the driver safety while using 4 and 5 point harness with HANS system. In further studies the model developed was used to identify factors affecting the safety of a rally driver.

The main objective of the work was to prepare the analysis of blood flow through the arteries taking into account the mechanical properties of the vessel wall. The mechanical properties of the specimens were determined using a testing machine MTS Insight 2, and digital image correlation (DIC). The developed numerical model allowed the assessment of the state of stress and deformation of the walls while the blood flow through the physiologically correct aorta.

This paper presents a morphological analysis of the skull shape in infants under one year of age. Three-dimensional measurements were performed on models generated from images in Mimics software. Subsequently, a multivariate statistical analysis of the measured dimensions was performed to determine key indicators of the skull shape. Eventually it was developed the norms of skull indices for children up to one year of age. Regular values of these indices were compared with abnormal values measured in patients with isolated craniosynostosis. With the use of these indices it is possible to perform a quantitative evaluation of head deformity.

SUMMARY Craniosynostosis is a skull malformation because of premature fusing of one or more cranial sutures. The most common types of craniosynostosis are scaphocephaly (with the sagittal suture fused) and trigonocephaly (with the metopic suture fused). In this paper we describe and discuss how finite element analysis and three-dimensional modeling can be used for preoperative planning of the correction of craniosynostosis and for the postoperative evaluation of the treatment results. We used the engineering software MIMICS MATERIALISE to obtain three-dimensional geometry from computed tomography scans, and applied finite element method for the sake of biomechanical analysis. These simulations help to improve the surgical treatment, making it more accurate, safer, and faster. Copyright © 2012 John Wiley & Sons, Ltd.

Improvised explosive device IED attack becomes main reason of casualties among coalition soldiers during military missions in Afghanistan and Iraq. In under-belly explosion scenario the most exposed on blast effects body part is leg. The aim of studies presented in this paper has been indication of factors enhancing lower leg injury risk during IDE attack. Model of soldier in KTO Rosomak (Polish army wheeled armoured vehicle) crew compartment created in Madymo software has been used for research. Results of simulations has been analysed and injury criteria has been determined.

This study aims to develop a testing methodology enabling the determination of mechanical properties of coronary arteries based on the example of porcine arteries using the MTS Insight 2 strength testing machine and digital image correlation (DIC). The conducted ballooning strength tests and static tensile tests revealed linear dependence between longitudinal and transverse strain of the arteries. The test results presented enable the evaluation and identification of the mechanical properties of porcine coronary arteries as well as prediction of the risk of the coronary artery rupture in the planned angioplasty and stent implantation procedures.

Rapid development of civilization, observed in the contemporary world, makes human life easier, but at the same time, it brings a lot of dangers and threats. Constant ‘race against the clock’, moving from one place to another, stress and fatigue result in a growing number of traffic accidents which claim the lives and health of adults as well as children. Most of the injuries are multiple traumatic injuries that affect two or more bodily organs or systems and cause damage to at least two body areas. They constitute exceptionally difficult, interdisciplinary therapeutic problem which is the most frequent cause of death and development of a disease in children over 3 years old.The aim of this research study was to conduct a retrospective analysis of physiotherapeutic procedures applied in the course of treatment of multiple trauma in children hospitalized in the Voivodship Medical Centre in Opole (Wojewódzkie Centum Medyczne).It was carried out in the group of 9 children aged 5-17 in the years of 2011-2013. As multiorgan injuries in children affect a developing body, they require a professional, interdisciplinary, therapeutic proceeding. The analysis of the ways of treatment shows that after securing basic vital functions of the children and the stabilization of their health, physiotherapy takes its turn. Its main role is to restore child’s physical ability, which was disordered due to the injury, as much as it is possible. According to the analysis of clinical and therapeutic progress in all 9 patients suffering from multi-organ injuries, an attempt has been undertaken to set the scheme of physiotherapeutic proceeding in such cases. Preparing the scheme, all basic rules of physiotherapeutic proceeding have been taken into consideration, namely, introducing therapeutic activities as soon as possible taking into account patient’s condition and the extent of damage/injury.The analysis proved that physiotherapy in multiple trauma is a complicated process that involves many techniques, methods and procedures. Moreover, every physiotherapeutic treatment ought to be adjusted individually to the patient depending on their condition and dysfunctions. Skilful management of the rehabilitation process significantly accelerates patient’s recovery to the extent of proper physical function, and limits the degree of disability after multipletrauma.

This chapter describes a method of engineering support of preoperative planning of surgical procedures with the use of engineering tools, such as state-of-the-art software for medical image processing, or a finite element method. The procedure of pre-operative planning consists in matching individual cases of incision sites and directions, visualization and selection of areas for resection as well as planning the technique of implant positioning and fixation. Also, the final visualization of the result of the planned medical procedure can be performed. This paper presents procedural propositions in surgery planning in the cases of corrections of the head shape in patients with craniosynostosis, corrections of the chest deformity such as pigeon chest and stabilization of the lumbar spine. 3D models created on the basis of computer tomography (CT) or magnetic resonance imaging (MRI) enabled it to conduct a biomechanical analysis as well as an objective quantitative and qualitative virtual evaluation of the surgical procedure. Preoperative planning support gives the physician an opportunity to prepare for the operation in a better way, which results in the selection of the best possible variant of an operative technique, reduction of time of the surgical procedure and minimization of the risk of intraoperative complications.

The paper discusses results of experimental research involving new generation of plate stabilizers used for the treatment of deformation of the front chest wall. Previous clinical monitoring revealed instances of minimal rotation, which caused destabilization of the anastomosis and pain in patients. In order to prevent this, transverse stabilizing plates were introduced to the structure of the stabilizer. The new structure of stabilizers was tested using two specially prepared research posts: 1 - which enables fastening of the plate stabilizers to a platform simulating human ribs, 2 - using a pig chest, to which plates were fastened according to the stabilization conditions in the stabilizer-chest structure. The tests recorded displacement values in selected areas of the plates in response to applied loading forces.

Craniosynostosis is a birth defect that causes one or more sutures on a baby's head to close earlier than normal. In effect the growing brain determines an abnormal skull shape and, which is more important and more dangerous, it causes an elevated intracranial pressure. The only treatment for children with craniosynostosis is surgical cranioplasty. More extensive procedures yield excellent results, particularly in older children with moderate to severe deformity. However, in children undergoing more extensive reconstructions an essential requirement is blood transfusion. They are also put at risk of complications. In this paper, the authors propose a method of preoperative planning based on three-dimensional modelling and biomechanical investigations. We used Mimics, 3-matic and ANSYS software for the process. The proposed preoperative planning improved the preoperative knowledge of deformation, shortened the time of surgery, and subsequently reduced blood loss during the procedure.

In this paper, the application of new visualization technologies in correction of funnel chest is presented. Often, such defects cause problems with breathing, and therefore, to improve the cardiorespiratory efficiency, a correction is required. The virtual model of chest was formulated to determine the strains and stresses after correction of deformation with using the stabilizing plate. From biomechanical point of view, the knowledge of the load-affecting stabilizer is necessary to select optimal parameters of the plate. The force-affecting plate that was used in the correction of chest deformation by Nuss method was determined on the basis of finite element model of funnel chest. The main aim of this work was to select the optimal thickness of plate. Calculations were conducted for three alternative constraints.

Craniosynostosis represents premature suture fusion of the fetal and neonatal skull. Pathogenesis of craniosynostosis is complex and probably multifactorial. Growth of skull bones is strictly connected with the expanding growth of the brain and cranial malformations or prematurely fused sutures cause abnormal head shape. In order to diagnose the craniosynostosis, physical examination, plain radiography, and computed tomography with 3D reconstructions are indispensable. Engineering software such as Mimics v.13.1 and 3-matic v.5.0 enables a 3-dimensional model of head to be generated, based on the pictures obtained from CT. It is also possible to indicate the distances between the characteristic anatomical points. These measures are helpful during planning the neurosurgical correction of the skull, because the possibility of strictly specifing incisions before surgery, which is very important to provide the maximal safety of a child.

In this work an attempt to determine state of load in funnel chest after correction of deformation by stabilizing plate was made. From biomechanical point of view the knowledge of load value affecting the stabilizer is necessary to select optimal parameters of the plate. The force value affecting the plate used for correction of deformation of the chest by Nuss’ method was evaluated on the base of funnel chest skeleton model formulated in ANSYS. Research works which aim was to select optimal thickness of the plate were carried out in next stage. In this work a parametric model of the plate was formulated, where thickness, length, width and flexion size of the plate are parameters of the model. Calculations were conducted for three alternative constraints.

The attempt to a new methodology creation, supported neurosurgical correction of trigonocephaly by engineers is presented in this paper. Trigonocephaly is an example of skull deformity, that wrong influence on child physical and psychological development. Conventional procedures in such cases are connected with invasive operation. Up to now neurosurgeons during pre-operation planning of bones correction, based on their own knowledge and experience. Modeling in biomechanics connected with modern visualization methods give new possibilities of engineer support for medical procedures. Three-dimensional model of deformed skull was created on the basis of CT scans with use of Mimics software. The model was transformed to FEM and used for suitable shape of forehead bone determination. Material properties of modeled bones were assumed on the basis of experimental researches. The geometrical model was presented in 3-dimensional virtual reality. It helps to better imagine about the real shape of skull hidden under head skin and take the best decision how to operate the example of trigonocephaly.

Purpose: The paper focuses on the numerical and experimental evaluation of the fluid flow inside chosen fragments of blood vessels. In the first stage of the study, the experimental tests were conducted using a research test stand, designed to be used in this evaluation. The study evaluated the blood flow through a silicone vessel with an implanted coronary stent. Methods: The PIV method was used in order to visualize the flow vectors inside a silicone vessel. Deformed vessel geometry implemented for computational fluid dynamics purposes was obtained owing to a non-linear simulation of the stent expansion (angioplasty process) in a silicone vessel. Additionally, a vessel model with a statistical 55% area stenosis and an irregular real vessel with an atherosclerotic plaque were also subjected to analysis from the hemodynamic flow point of view. A vessel with a statistical stenosis was also used to simulate the angioplasty process, which resulted in obtaining a flow domain for the vessel with an atherosclerotic plaque after the stent implantation. Results: For each case, distributions of parameters such as OSI or TAWSS were also analyzed and discussed. The areas of low TAWSS values appear close to the stent struts. Conclusions: Stents with increased diameters, compared to the normal vessel diameter, create a higher risk of occurrence of the areas with low WSS values. Excessive stent deformation can cause inflammation by injuring the vessel and can initiate the restenosis and thrombotic phenomena through the increased vessel diameter.

The article assesses the strength and structural parameters of load-bearing layers of metal biobearings made of CoCrMo alloy. The research material consisted of unicompartmental knee joint endoprostheses used in the human body, removed due to excessive wear. No patient participated in the examinations. The endoprostheses used as research material underwent the liquidation procedures in the hospital, which has all necessary permissions and certifications to perform endoprosthetic procedures. Endoprostheses selected for the examinations had been used for 6 to 12 years at similar load conditions as declared by the patients, i.e., body weight of F = 835 N, declared activity expressed as the number of load cycles up to 100 thousand/year, and no artificial joint infections. To assess the homogeneity of the research material, the analysis of chemical composition using a Joel scanning electron microscope with EDS (Energy-dispersive X-ray spectroscopy) was made to exclude endoprostheses with various alloying additives. Microscopic examinations were performed using the Phenom XL microscope, while the wear surface was examined using a Keyence VHX-900F microscope. Several experimental tests were also carried out on load-bearing surfaces to assess changes in strength parameters of the base material after a known life cycle and load conditions. Material hardness using the Vickers method, yield point, critical value of stress intensity coefficient, and the coefficient of friction &micro, were evaluated. The examinations allowed for the systematization of wear in the knee and femoral components of unicompartmental hip endoprostheses. The statistical evaluation of the number and costs of hip joint replacement surgeries in Poland was also made.